A known smart entry system (a locking system) applicable for a vehicle door opening/closing device is disclosed in a European Patent Laid-Open Publication published as No.1,006,028 A2 which corresponds to a Japanese Patent Laid-Open Publication published as No. 2000-160897. The disclosed smart entry system enables the detection of whether or not a user carrying a portable station (i.e. a remote-controller) has come close to or been away from a vehicle door. The vehicle door is hence automatically locked or unlocked in response to the detected result. In light of foregoing, the smart entry system enhances the convenience for opening/closing the vehicle door and the safety thereof.
The above-described publication discloses the automatic unlock/lock operation of the vehicle door. However, it does not appear to disclose how the vehicle door unlocked/locked condition is warned to the user. According to the disclosed smart entry system, it may be difficult for the user to acknowledge whether or not the vehicle door has been actually locked without any warning to the user. Therefore, recent requirements have been made to warn the user that the vehicle door has been locked or unlocked in some way.
According to a Japanese Patent Laid-Open Publication published as No. 2000-45593, disclosed are an outputted light control signal and an outputted sound control signal. The light control signal is referred to for determining an amount or quality of light emitted from a luminous member such as a dome light for illuminating a vehicle interior, a head lamp, and a tail lamp in accordance with a lightness outside the vehicle. The sound control signal is referred to for determining a volume or quality of a sound emitted from a sounding member in accordance with the lightness outside the vehicle. More particularly, when it is as light as day outside the vehicle, the light emitted from the luminous member may not be sufficient as a single parameter for recognizing the vehicle door condition. In this case, the light emitting amount is reduced and a buzzer sound can be used along with the emitted light as the parameter for recognizing the vehicle door condition. On the other hand, when it is as dark as evening or night outside the vehicle, the buzzer sound volume is reduced and the emitted light can be used along with the buzzer sound as the parameter for recognizing the vehicle door condition. Therefore, the user can easily acknowledge whether the vehicle door has been locked or unlocked.
However, the luminous member such as the dome light for illuminating the vehicle interior, the head lamp, and the tail lamp is provided at a distance from a door handle manually operated when the user intends to open or close the vehicle door. Therefore, according to the vehicle door opening/closing device, in which the vehicle door is automatically locked or unlocked based upon the manual operation of the door handle, the user may not be surely acknowledged of the vehicle door condition in view of a visual field. In other words, the luminous member such as the dome light, the head lamp, and the tail lamp is beyond the user's visual field so that the user may not be surely acknowledged of the vehicle door condition.
The present invention therefore seeks to provide an improved vehicle door opening/closing device capable of surely warning the user of the vehicle door condition (i.e. locked or unlocked).